Various distractions can divert the attention of a driver of a vehicle. Such distractions can be sourced from within a vehicle or from without and may last over a widely varying length of time. When such a distraction diverts a driver's attention at the same time as when a hazardous condition arises, accidents can result.
Various warning systems are known, and others are being developed, to alert a vehicle driver to the existence of potential hazards in the driving environment. For example, in-vehicle radar systems can detect and warn when a collision appears possible or likely. Image processing systems can detect and warn when a traffic signal has changed to a red color. Wireless warning beacons can provide a wireless signal indicating proximity of a given roadside hazard. In each of these examples, indicia in various forms are typically provided to the driver to warn of the corresponding condition.
Unfortunately, such indicia typically represent a variety of compromises. The degree of attention by which the indicia draw attention to themselves can be inappropriate to a given set of circumstances and variables. For example, under some circumstances, the indicia can be redundant to information of which the driver is already aware. When this happens, the indicia can be an annoyance to the driver and, worse, can be a diversion that may itself distract the driver from dealing with the circumstance at hand. Under other circumstances, such as when the driver is already operating under a considerable cognitive load (as can occur when the driver is significantly distracted by some other condition), the indicia may be ineffective to break the driver's distraction in sufficient time to permit appropriate preemptive actions to be taken or to otherwise deal with the hazardous condition.